<?php
    // +----------------------------------------------------------------------
    // | ThinkPHP [ WE CAN DO IT JUST THINK ]
    // +----------------------------------------------------------------------
    // | Copyright (c) 2006~2015 http://thinkphp.cn All rights reserved.
    // +----------------------------------------------------------------------
    // | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
    // +----------------------------------------------------------------------
    // | Author: yunwuxin <448901948@qq.com>
    // +----------------------------------------------------------------------
    namespace think\console\output\formatter;
    class Stack {
        /**
         * @var Style[]
         */
        private $styles;
        /**
         * @var Style
         */
        private $emptyStyle;

        /**
         * 构造方法
         * @param Style|null $emptyStyle
         */
        public function __construct(Style $emptyStyle = null) {
            $this->emptyStyle = $emptyStyle ?: new Style();
            $this->reset();
        }

        /**
         * 重置堆栈
         */
        public function reset() {
            $this->styles = [];
        }

        /**
         * 推一个样式进入堆栈
         * @param Style $style
         */
        public function push(Style $style) {
            $this->styles[] = $style;
        }

        /**
         * 从堆栈中弹出一个样式
         * @param Style|null $style
         * @return Style
         * @throws \InvalidArgumentException
         */
        public function pop(Style $style = null) {
            if (empty($this->styles)) {
                return $this->emptyStyle;
            }
            if (null === $style) {
                return array_pop($this->styles);
            }
            /**
             * @var int   $index
             * @var Style $stackedStyle
             */
            foreach (array_reverse($this->styles, true) as $index => $stackedStyle) {
                if ($style->apply('') === $stackedStyle->apply('')) {
                    $this->styles = array_slice($this->styles, 0, $index);
                    return $stackedStyle;
                }
            }
            throw new \InvalidArgumentException('Incorrectly nested style tag found.');
        }

        /**
         * 计算堆栈的当前样式。
         * @return Style
         */
        public function getCurrent() {
            if (empty($this->styles)) {
                return $this->emptyStyle;
            }
            return $this->styles[count($this->styles) - 1];
        }

        /**
         * @return Style
         */
        public function getEmptyStyle() {
            return $this->emptyStyle;
        }

        /**
         * @param Style $emptyStyle
         * @return Stack
         */
        public function setEmptyStyle(Style $emptyStyle) {
            $this->emptyStyle = $emptyStyle;
            return $this;
        }
    }
